Re: proc fs and shared pids
Systemkennung Linux (linux@mailhost.uni-koblenz.de)
Fri, 2 Aug 1996 12:50:20 +0200 (MET DST)
> Is a 16-bit pid enough? I could imagine wanting some extra bits
> to specify what processor node so that it would be easy to find
> the process in a Linux supercomputer. (if process migrates, drop
> the bits and search all nodes) I could also imagine running out
> of pids - BTW, does the kernel check for that or just get stuck?
> There are only around 30000 pids, and some systems have that many
> processors already.
The kernel can't run out of pids because before that happens the
process table, a static array, will overflow. The size of the
process table can be configured in <linux/tasks.h> and defaults
to 512. If this limits is raised beyond 32768 get_pid() in
kernel/fork.c will handle the case of running out of pids.
Though some people are playing with parallel systems under Linux
this case is pretty academic ...
Ralf